1. Field of the Invention
The present invention relates to an image processing apparatus having a communication function.
2. Related Background Art
A large size display apparatus with a communication function has been known by U.S. patent application Ser. Nos. 07/996,880, filed Dec. 12, 1992 and 07/960,288 filed Oct. 13, 1992. The display apparatus with the communication function displays information such as images, characters and graphics to many non-specified people at a public place such as station, airport or event place. It receives image data to be displayed through a communication line and displays it on a display screen.
A prior art display apparatus with a communication function uses a so-called magne-stylus recording system as shown in FIG. 17.
In FIG. 17, image display means 1508 having the following units is provided in an apparatus main unit 1507.
Numeral 1509 denotes a display belt which forms a display screen, and it comprises an endless belt-like member having a white surface. It is spanned over a pair of vertically arranged rollers 1510 and 1511 for driving it and supported planarly to a display unit 1512. Numeral 1513 denotes image forming means for forming an image to be displayed on the display belt. The image is formed by electro-statically depositing conductive magnetic toner T to the display belt 1509 by a method disclosed in Japanese Patent Publication No. 51-46707.
The magnetic toner T is carried on a non-magnetic cylinder 1515 by the station of a rotary magnet 1514 and supplied to a recording electrode 1516. A signal sent to the record electrode 1516 through a line 1505 is converted to a display image signal by a receiving unit 1517 and a voltage determined by the display image signal is applied by a driver 1518 to the display belt 1509 so that the magnetic toner T is deposited on the display belt 1509 to form a desired image. The belt 1509 is rotated and displayed on the display unit 1512.
A control unit and a communication unit are configured as shown in FIG. 16.
The receiving unit 1517 comprises a receiver 1504 for interfacing with a communication line 1505 such as a telephone line, a control unit 1501 including a microprocessor and a memory, and a screen display unit 1503 including the display mechanism of FIG. 17 and a driver therefor.
An operation to display the image data received from the communication line is explained with reference to FIG. 15.
The control unit 1501 receives the image signal sent from the line 1505 by the receiver 1506 (step S1501) and receives the image information by the receiver 1506 and transfers them to the screen display unit 1503 (step S1502).
However, the prior art apparatus merely displays the image sent from a terminal device such as a facsimile device and has the following short-comings.
(1) The control to the display is limited to preset control and the control method cannot be altered from a distant place.
(2) Since there is no output means in the display apparatus, it is not possible to inform the switching of the displayed image at the switching time of the display by a voice output.
(3) When a new image is received, the previously stored image is erased. In order to sequentially switch the display, it is necessary to transfer the image data each time but high speed display switching is not possible.
(4) A plurality of apparatus may be provided and used, but because of a lack of means for remotely synchronizing timers of the respective apparatus, it is not possible to synchronize the displays of the plurality of apparatus by the timer control. Further, the timers must be adjusted at the installation places of the apparatus.
(5) In a multi-station transmission mode, the control command and the image data must be sequentially sent to each of the image display apparatus. This is time consuming.
A remote control method to a facsimile device at a distant place includes a method which uses a DTMF signal (tone signal) or a V21 modem signal.
In the prior art apparatus, however, when the facsimile device at a distant place is to be remotely controlled, command/response communication can be made only by one predetermined control signal such as DTMF signal (tone signal) or V21 modem signal.
When the DTMF signal is used, for example, proper communication may not be attained if the line status is not good or an affect by an echo is included such as in an overseas line.
The DTMF signal is basically sent by a telephone set and the V21 modem signal is sent by a modem which conforms to the V Series Recommendation. Namely, a terminal which remotely controls the apparatus is determined by the signal type. Thus, if an appropriate terminal is not available, the remote control is not attained. In case of the V21 modem signal, a personal computer is required even for a simple control and hence the operation is complex.
The above problems are not limited to the facsimile device but common to various communication apparatus.